Quinn's87RE

85' 22RE

The Problem:
Runs good when hot - steady idle and good power. When cold it barely, if at all, will stay running on her own. I can get it to stay running if I gas her. I can also get it to fire right up at 800 RPM if I loosen the flat head idle adjustment screw. But then, after she warms up she'll idle up at 1500 RPM.

Where I'm at:
I put a "new" TPS in according to 4crawler and page FI-59 of the FSM but I can't get it exactly in spec. A couple sample TPS settings, in k ohms I've tried while driving the truck:,

Test #A1 - .84k Test #B1 - .88k________________________Spec = .2k - .8k
Test #A2 - .24k Test #B2 - .86k________________________Spec = < 2.3k
Test #A3 - Inf. Test #B3 - Inf.__________________________Spec = Inf.
Test #4 - Always in spec.
Test #5 - Always in spec.

After each test the truck was timed, with the terminals jumped, and tried on both 5deg and 7deg BTDC (engnbldr .269 cam). I began to suspect the IACV but I pulled it and it tested fine electronically and mechanically. The following parts also check out OK electronically: fuel pump, cold start injector, AFM, solenoid resistor, start injector time switch, battery, and water thermo sensor. Also, parts that i have replaced over the last year that might conceivably be related to this are the ECU, ignition switch, ignition control module, ignition coil, wires, plugs, knock sensor, starter, and fuel filter.

During both A and B series test I can loosed that top idle screw to start cold and she'll run at 800 RPM but warms up to 1500 RPM. I then re-time and set the idle to 800 RPM where she idles steady, sounds good, good power. I'll then shut off the truck, and she doesn't even have to fully cool off before the process starts over again. This makes me think it's air related. Before I replaced the TPS (it was bad) all the settings (timing, idle screw) were set crazy off to compensate.

Are my slightly out of spec readings on my TPS really giving me this much trouble? Where could I look next? What am I missing that is air related? Is it not air releated? Help!!!!!


I also ran her with a third slightly out of spec. TPS readings in k ohms:

Test #1 .79k
Test #2 .14k
Test #3 .25k
Test #4 - Always in spec.
Test #5 - Always in spec.

During this setting she was on an idle loop where she would start at 800 RPM, steadily rise to 1200 RPM, drop fast to 700 RPM, and then repeat every thirty seconds or so.

coryc85

When you say you tested the IACV, can you be more specific about how you tested it? Did you put it in freezer to check that it opens on its own?

It's your EGR hooked up correctly? Could it be hooked up such that it is opening when engine is cold?

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Quinn's87RE

I tested it electrically, which was OK. Then I took off the cover plate and it had an opening like is pictured in the FSM. There was no gunk build up and the valve didn't stick when i puished it open and close. I guess I should have put it in the freezer, it looked like it was in good shape though.

Hmm, I don't know about the EGR being hooked up all correctly. I guess it's another place to start poking at. Is there an obvious way that the EGR would be hooked up so it would open when cold?

ksti

I'm also curious how you tested the IACV "electrically"

Quinn's87RE

You disconnect the electrical plug on the back of the unit and read the resistance between the two prongs - should read b/w 20-59 ohms.

coryc85

There are some on-vehicle checks for the IACV in the FSM, so you can start with those. It involves pinching the air hose to see if idle changes. I guess you will have to adjust idle up so it actually runs when cold.

As for the EGR, I guess there are 2 possible scenarios: vac could possibly be hooked up such that it is operating even when engine is cold, you'll have to look at the routing to figure it out. the other possiblity is maybe it is stuck open all the time. This is just pure speculation though, I think the IACV is more likely a problem, I would check it out as fully as possible before doing other things.

Melrose 4r

I am very interested in what you find. My 22re won't fast idle when cold and everything I've tested looks normal/functional.
There is an air temp sensor somewhere in the air flow meter housing according to my shop manual. I don't know how to access it or test it though.
From experience, EGR stuck open on a 22R makes an awful internal vac leak and the vehicle will be so down on power if it runs at all. Be sure your vac
lines are going where they are supposed to, not rerouted by some previous owner.

Quinn's87RE

In between hunting season and work I won't be able to get back at her until maybe Monday or Tuesday.

EGR may be a poignant direction to take - I don't have a pressure gauge diagnostic tool yet though, which is key for most EGR tests. Yeee new tools in my future!

My IACV really seems to be working. This part may take a back burner for now. I'm 98% sure it is functioning correctly.

It sounds like none of y'all think the slight protrusions of my TPS results are likely the cause of my woes? If y'all have specs of what your TPS is running at - PLEASE post them up!

Quinn's87RE

My vac lines, from what I can tell, are all set according to the FSM. What is this you say about a air temp sensor? I don't recall any mention of that in the FSM and I have had the air meter apart to diagnose. There really isn't much to it and I didn't see anything like that.

Melrose 4r

I don't want to send you barking up the wrong tree but it's a mystery to me also...later when I am home I can report the page of the service manual I saw it on. Did you already say you checked the H20 temp sensor?

sorry, you did say that. And on that cycling problem where the idle runs up and drops off, I had an MR2 that did that back in the 90s. Too bad I don't recall exactly what the problem was but it was simple. possibly h20 temp sensor.

Melrose 4r

1986 truck and 4runner repair manual, pg.FI-56, Airflow meter, shows resistance measurements between terminals and Temp dependent resistances betweeen terminals E2 and THA.

​​​​​​​I think i'll go measure this on my own truck...

Melrose 4r

On the idle cycling problem, lots of videos on youtube but one common fix seems to be replacing the o-ring on the idle adjustment screw or wrapping the threads with some teflon tape. The deteriorated o-ring causes a vacuum leak.

Melrose 4r

After i wrote this i went and pulled my own idle screw out and found it was quite carboned up. So check that. I shot its hole and other vac ports on the throttle body with carb cleaner and ungunked the idle screw with a wire brush. Just something else to check.

All the resistance measurements for the airflow meter checked out fine on mine.

Quinn's87RE

This seemed to stop my fluctuating idle! I would encourage everyone to do this first as it is a heck of a lot easier than everything else I did. I used some thread sealant tape I had in a kit for air hose couplings.

Still there is a problem. It starts up good cold, idles good hot, but does terrible on warm starts. I have read info about a 1987 Toyota Service Bulletin...

I can find these parts online for about $315 total. I would really not like to spend that much. Any good tests to make sure this is the problem? I unplugged them during a warm start but it didn't help. Is this a definitive test? Any other ideas for bad warm starts?

Quinn's87RE

I swear all the tests on my AFM were OK, I suppose I could have estimated the temperature wrong and therefore misinterpreted my results. Re-test again soon. I came across this:

'

I only poured two glasses of ice water on it, it didn't even feel hot to begin with, but it seemed to help a little. I then unplugged the AFM and tried to start her up warm - she fire right up to the right idle speed but died shortly after. I'll re-test my AFM again andI have another AFM i can test and swap out if needed this week, but sadly I don't time tonight.

se7enine

iTrader: (2)

Time to hunt down that illustrious 85 Supra AFM.

Melrose 4r

Edit: my mistake...how do you delete a post anyway?

SunSetPrez

Not to hijack your thread but I am having some tps issues. No CEL but test 4 always comes out open. Think this TPS is bad?